1. Field of the Invention
The present invention relates to a radio communication system, and a method and radio communication apparatus thereof where a connection between a controlled radio communication apparatus and a controlling radio communication apparatus is registered.
2. Description of the Related Art
In a radio communication system for carrying out radio communications using controlled radio communication apparatuses, a controlled radio communication apparatus must register a connection with a controlling radio communication apparatus, whereby the controlling radio communication apparatus conducts polling for controlled radio communication apparatuses with registered connections and a sending operation of a controlled radio communication apparatus is permitted by the polling. Since a sending operation from a controlled radio communication apparatus is permitted by polling and the polling is conducted only with respect to registered connections, a radio communication apparatus whose connection is not registered cannot conduct a sending operation. In addition, if the controlling radio communication apparatus does not receive a control signal from a controlled radio communication apparatus whose connection is registered, the registered connection is invalidated. Thus, if a connection between a controlling radio communication apparatus and a controlled radio communication apparatus is interrupted for even a moment due to an unstable communication environment, a registered connection of the controlled radio communication apparatus may be invalidated. Since connection registration cannot be carried out automatically, it would be necessary to register the connection again, and radio communication becomes unstable.
The present invention was made in consideration of the above problem and has as its object the provision of a radio communication system and method capable of automatically registering a controlled radio communication apparatus.
It is another object of the invention to provide a radio communication system and method capable of carrying out stable radio communication.
Other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification and the drawings.
To solve the above-described problems and to achieve the objects of the invention, in a radio communication system of the present invention, a first radio communication apparatus controls a single or a plurality of second radio communication apparatuses, the first radio communication apparatus sends vacant slot information indicative of vacant time division multiplexing time slots to a second radio communication apparatus, the second radio communication apparatus sends a connection register request signal using a vacant time division multiplexing time slot based on the vacant slot information, the first radio communication apparatus registers the connection of the second radio communication apparatus by allocating the vacant time division multiplexing time slot to the second radio communication apparatus that sends the connection register request signal, and the second radio communication apparatus sends a control signal using the time division multiplexing time slot allocated by the first radio communication apparatus.
In accordance with an embodiment of the present invention, the first radio communication apparatus sends vacant slot information indicative of vacant time division multiplexing time slots to the second radio communication apparatus. A second radio communication apparatus sends a connection register request signal to the first radio communication apparatus using a vacant time division multiplexing time slot based on the vacant slot information. Then, the first radio communication apparatus allocates the vacant time division multiplexing time slot to the second radio communication apparatus that sends the connection register request signal based on the connection register request signal received from the second radio communication apparatus using the vacant time division multiplexing time slot. Next, the second radio communication apparatus sends a control signal using the time division multiplexing time slot allocated by the first radio communication apparatus.
According to an embodiment of the present invention, a second radio communication apparatus whose connection is not registered specifies a vacant time division multiplexing time slot based on the vacant slot information received from a first radio communication apparatus, and sends a connection register request signal to the first radio communication apparatus using the vacant time division multiplexing time slot. As a result, the second radio communication apparatus can automatically register the connection without receiving polling from the first radio communication apparatus.
According to an embodiment of the present invention, the first and second radio communication apparatuses confirm communication quality between them based on the control signal received from one another on the time division multiplexing time slot.
According to an embodiment, the radio communication is carried out using a frame as a unit, and the frame includes a first period during which the vacant slot information is sent and a second period which is allocated to the plurality of time division multiplexing time slots.
The frame may further include a third period during which a data signal is sent and received, where a second radio communication apparatus whose connection is registered may send and receive a data signal using the third period.
According to an embodiment, a second radio communication apparatus asynchronously sends or receives a data signal using the third period, and the first radio communication apparatus controls the communication of the data signal of the second radio communication apparatus by way of polling.
In accordance with an embodiment of the invention, a first radio communication apparatus judges whether a connection registration of a second radio communication apparatus should be allowed or rejected based on the connection register request signal received from the second radio communication apparatus, and a result of the judgment is sent to the second radio communication apparatus using the third period.
According to an embodiment of the invention, when a first radio communication apparatus does not receive a control signal that should have been received using the time division multiplexing time slot from a second radio communication apparatus for a predetermined period of time, the first radio communication apparatus cuts the communication of the second radio communication apparatus, but holds, during the predetermined period of time, the connection register of the second radio communication apparatus even though the first radio communication apparatus does not receive the control signal from the second radio communication apparatus. Thus, even if the first radio communication apparatus does not receive the control signal from the second radio communication apparatus due to an unstable radio communication environment, the first radio communication apparatus can hold the connection register of the second radio communication apparatus. As a result, it is possible to effectively prevent the connection of the second radio communication apparatus from being cut frequently, and prevent connection registration from being frequently repeated, and stable radio communication can be carried out.
The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the apparatus embodying features of construction, combination(s) of elements and arrangement of parts that are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.